William a



(No Model.) 8 W. A. JOHNSON.

ELECTRIC LIGHT CIRCUIT GUT-OFF SWITCH. No. 390,481. Patented Oct. 2,1888.

PATENT OFFIQEQ "WILLIAM A. JOHNSON, OF TORONTO, ONTARIO, CANADA.

ELECTRlC-LlGHT-CIRCUIT CUT-OFF SWITCH.

SPECIFICATION forming part of Letters Patent No. 390,:81, dated OctoberApplication filed November 23, 1887. Serial No. 256,090. (Xo model.)

To aZZ 1117mm it may concern.-

Be it known that 1, WILLIAM ASAIIEL JOHNSON, of the city of Toronto, inthe county of York, in the Province of Ontario, Canada, manufacturer,have invented a certain new and useful Improvement inEIectricLight-Oircuit Out-Off Switches, of which the following is aspecification.

The object of the invention is to design a si mply-constructedelectric-light-circuit cut-' off switch by which the current may becompletely cut off from the loopcircuit; and it con sists, essentially,of two metal levers coupled together by an insulated connection andpivoted upon the binding-posts of the dynamocircuit, the said leversbeing arranged in connection with the contact-plates connected,respectively, with the binding-p0sts in the loop circuit and with one ofthe binding-posts in the dynamo circuit in such a manner that thecurrent may be thrown on and off the loop circuit by the simpleadjustment of the levers in such a manner that the levers will makecontact with the binding-posts of one circuit before breaking contactwith the others, all as more fully hereinafter described and claimed.

Figure 1 represents a view of my improved switch set so that the loopcircuit is completely cut o'tl'. Fig. 2 shows the switch set so that thecurrent shall pass through theloopcircuit.

A and B represent the binding'posts ol' the dynamocircuit, and O D thebindiugposts of the loop circuit. The lever-E is pivoted upon and is incontact with the binding-post A, and the lever F is pivoted upon and incontactwith the binding post B. These two levers E and F are coupledtogether by the insulated link G, so'that themovement of one lever shallbe communicated to the other.

H is a contact-plate connected to the hindlug-post C, and extendingtoward the leverE, as shown. I is a similar cont-actplate connected tothe bindingpost D and extending toward the lever F. J is also acontact-plate connected to the post A and extending past the post 0toward the lever F, as indicated.

\Vhen my switch is set as shown in Fig. 1, the current will pass fromthe binding-post B along the lever F, and then through the contactplateJ, through the binding-post A, and back to the dynamo, and as bothbinding-posts O and D are completely isolated no current can possiblyreach the loopcircuit. "When the switch is set as shown in Fig. 2, thecurrent from the dynamo enters the binding-post I3, along thecontact-plates F and I, and thence into the loop'circuit through thebinding-post D, and back again to the dynamo, through the binding-postO, contactplate H, lever E, and binding-post A.

It will be noticed that the distance between the contact-plates I and Jis less than the width of the lever F. Consequently the said lever Fcomes in contact with one of the said plates before it loses contactwith the other.

It will be seen that by employing a cut-off switch such as the onedescribed a loop-circuit running into a building may be completely cutoli' from the main circuit, leaving the wires and lamps within thebuilding pcr fectly safe to handle, and that the switch makes contactwith the plates H and I before breaking contact with the plate J, andvice versa, so that there will be no spark and no danger from fire. Thisis important.

IVhat I claim as my invention is- 1. The combination,with thebinding-posts A B CD, of two levers pivoted upon the binding-posts A B,and connected to move to gether, the contactplates II I, connected tothe binding-posts O D, respectively, and the inclined contact-plate J,connected with the binding-post A and extended between the plates H I,substantially as and for the purposespecified.

2. The combination, with the binding-posts A B O D, oftwo levers pivotedupon the binding-posts A 1-3 and connected to move together, thecontact-plates II I, connected to the binding-posts C D, respectively,and the inclined contact-plate J, connected with the binding-post A andextended between the plates H I, the space between the plates I J beingless than the width of the lever F, substantially as and for the purposespecified.

Toronto, October 28, 1887.

IVIIJIJIARI A.

JO HNSON.

